Ammonia → 1,2-Benzisothiazol-3-amine

3-Amino-1,2-benzisothiazoles have hitherto been manufactured by other methods, since they differ in structure from the above benzisothiazoles. U.S. pat. No. 3,692,795 described a reaction of compounds of the formula ##STR1## with hydroxylamine in the presence of organic solvents at an elevated temperature, followed by hydrolysis of the resulting N-acyl-3-amino-1,2-benzisothiazoles in the presence of excess acid at the reflux temperature, treatment of the reaction mixture with alkali and extraction of the end product with, for example, ether. 3-Amino-1,2-benzisothiazole has also been prepared, using a 5-stage synthesis (Berichte der deutschen Chemischen Gesellschaft, 58 (1925), 2,095), using thionaphthene-2,3-dione, a compound difficult to obtain, as the starting material; the reaction stages comprise the manufacture of 3-carbamyl-1,2-benzisothiazole by reacting the thionaphthene-2,3-dione with ammonia and hydrogen peroxide, manufacture of the hydrazide, azide and urethane and, finally, decomposition to give 3-amino-benzisothiazole.

1. extractionextraction of the end product with, for example, ether
2. custom3-Amino-1,2-benzisothiazole has also been prepared
3. customa 5-stage synthesis (Berichte der deutschen Chemischen Gesellschaft, 58 (1925), 2,095)
4. customa compound difficult to obtain, as the starting material
5. customthe reaction stages

ORD record

ord-11cb02671eab4984a5329d7e7d2f5374

Source dataset

uspto-grants-1979_02

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US04140692